Injection mold having a movable slide member

ABSTRACT

An injection mold including a connecting structure for separating confronting faces of a slide member and a mold base, respectively, during a movement of the slide member. In accordance with several embodiments of the invention, the connecting structure may include a compressible member such that the slide member is biased away from the mold base, and wherein a positive contact between the confronting surfaces is configurable in response to an applied clamping force between the slide member and the mold base. In accordance with an alternative embodiment of the invention a cam arrangement links the slide member and the mold base enabling a positive contact between the confronting surfaces when the slide member is arranged in the in-mold position, and providing a gap between the confronting surfaces during at least a portion of an interval when the slide member is moving.

TECHNICAL FIELD

The present invention relates, generally, to molding systems, and moreparticularly, but not exclusively, to an injection mold of a moldingsystem configured for producing preforms.

BACKGROUND OF THE INVENTION

U.S. Pat. Nos. 5,736,173 and 6,569,370 disclose a preform injection moldincluding a stripper plate that supports a wear plate on its uppersurface. Opposed slide bars, having neck rings mounted thereon, areslidably supported by the wear plate.

U.S. Pat. No. 6,450,797 discloses molding apparatus including a pair ofslide bar inserts that are laterally movable into and out of engagementwith other mold components.

U.S. Pat. No. 6,799,962 discloses a stripper assembly for an injectionmolding machine. The assembly comprises a slide bar pair consisting of afirst slide bar and a second slide bar. Transmission means isoperatively coupled to the first slide bar and the second slide bar totransform movement of the first slide bar in one direction into movementof the second slide bar in an opposite direction.

FIG. 1 is a cross-sectional view through a portion of an injection moldof U.S. Pat. No. 6,569,370. Generally, the mold is shown to include amold base 16 comprising a core plate 3, a stripper plate 17, and acavity plate 10, having a stack 1 of molding inserts arranged therein.FIG. 1 shows the mold in a mold-closed position ready for injection ofthe plastic into the mold. The stack 1 includes a mold core 2 fittedinto the core plate 3 and retained therein by a lock ring 4 and bolts 5.The mold core 2 contains a cooling tube 6 for the transmission ofcooling fluid from a source within the core plate 3 to remove heat fromthe injected material in the mold cavity 7 and solidify the molded partin the mold cavity 7. The stack 1 comprises a set of complementarymolding inserts including a cavity insert 8 and an adjacent gate insert9 that are retained in the cavity plate 10 by a cavity flange 11 andbolts (not shown). Cooling channels 12 circulate cooling fluid from asource through the cavity insert 8 and gate insert 9 to remove heat fromthe injected material. The mold base 16 also includes a pair of slidebars 15A and 15B that are slidably supported on a wear plate 19, itselfmounted on the stripper plate 17. The slide bars 15A, 15B are configuredfor carrying a pair of neck rings 13 and 14 of the mold stack 1 betweenan in-mold position and an out-mold position. The wear plate 19 issacrificial material and reduces the wear between the slide bars 15A,15B and the stripper plate 17 when the neck rings 13 and 14 are movedapart by the slide bars 15A, 15B to release a molded part from the moldcavity 7. Cooling channels 18 circulate cooling fluid from a sourcethrough the neck rings 13 and 14 to remove heat from the injectedmaterial. Molten material is conveyed to the mold cavity via a hotrunner nozzle, hot runner manifold and hot runner stacks.

FIG. 2 is a partial perspective view of a known slide bar and stripperassembly that may be used with the stack 1 of FIG. 1. In this assembly,the slide bars 21A and 21B are linked to the mold by a connectingstructure 61 that includes connecting bars 22A and 22B, respectively,and a pair of gibs 23A and 23B bolted to the stripper plate 25, forslidably arranging the connecting bars 22A and 22B in a guide that ispreferably provided as a groove 26 configured in the stripper plate 25.The connecting bars 22A and 22B travel along the stripper plate groove26 to activate the slide bar 21A and 21B, between an in-mold and anout-mold position, to open and close the neck rings in the mold. Forpurposes of illustration, a single pair of neck rings 20A and 20B isshown. Wear plates 27, 28 are located between the slide bars 21A and 21Band the stripper plate 25 to reduce wear of the slide bars 21A and 21Band stripper plate 25. Because the wear plates 27, 28 do wear, clampingforce cannot be reliably applied therethrough but instead passes alongthe mold stack. When the clamping force A (see FIG. 1) going throughmold stack 1 becomes so high that it could start to wear stackcomponents, it becomes necessary to add clamping force blocks 29, shownwith reference to FIG. 1, outside the immediate area of the moldcavities to take excess clamping force.

As shown in FIG. 2, in the prior art, gibs 23A, 23B are attached to thestripper plate 25 to constrain the connecting bars 22A and 22B withinthe groove 26. The gibs 23A, 23B are made from a stiff material such asan aluminum-bronze extruded bar stock sold under the registered trademark ‘Ampco 18’ by Ampco Metal S. A. Corp of Switzerland (i.e. Young'sModulus of about 117 GPa). When the connecting bars 22A and 22B aremoved along the groove 26, a corresponding movement of the slide bars21A and 21B, linked thereto, between the in-mold and the out-moldpositions, causes the neck rings 20A and 20B, respectively, to movebetween an open and a closed configuration. The connecting bars 22A and22B are moved along the channel by a cam arrangement, not shown, or byany other suitable means that may be apparent to those skilled in theart. The wear plates 27, 28 between the slide bars 21A and 21B and thestripper plate 25 separate the stripper plate 25 from the slide bars 21Aand 21B to prevent wear of the confronting surfaces of the slide bars21A and 21B and stripper plate 25. However, the existence of this wearplate 27, 28 does not provide for a reliable application of clampingforce between the slide bars 21A and 21B and the stripper plate 25 oncethe wear plate becomes worn.

SUMMARY OF THE INVENTION

An embodiment of the present invention mitigates the foregoing problems,at least in part.

In accordance with a first aspect of the present invention, there isprovided an injection mold including a mold base having a confrontingsurface, a slide member having a complementary confronting surface, anda connecting structure slidably linking the slide member to the moldbase for movements thereof between an out-mold and a in-mold position.The connecting structure is further configured to maintain a gap betweenthe confronting surfaces during at least a portion of the movement ofthe slide member between the out-mold and the in-mold positions so thatwearing of the confronting surfaces is reduced.

A technical effect of the present invention is to reduce wearing betweenthe slide member and the mold base.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the exemplary embodiments of the presentinvention (including alternatives and/or variations thereof) may beobtained with reference to the detailed description of the exemplaryembodiments along with the following drawings, in which:

FIG. 1 is a cross sectional view through a known stack of a knowninjection mold for molding a preform;

FIG. 2 is a partial perspective view of a known slide bar and a knownstripper plate assembly;

FIG. 3 is a cross sectional view of a mold in accordance with a firstembodiment in a mold-closed position;

FIG. 4 is a cross sectional view through the mold of FIG. 3 in amold-open position;

FIG. 5 is a cross sectional view through the mold of FIG. 3 with themold fully open and neck rings separated;

FIGS. 6A and 6B are partial perspective views of the mold of FIG. 3;

FIGS. 7A and 7B are partial perspective views of a mold in accordancewith a second embodiment; and

FIG. 8 is a partial sectional view of a mold in accordance with a thirdembodiment; and

FIG. 9 is a cross-sectional view of a mold according with a fourthembodiment; and

FIG. 10 is a partial perspective view of a mold in accordance with afifth embodiment;

FIG. 11 is a perspective view of a stripper assembly of a mold inaccordance with a sixth embodiment;

FIG. 12 is a perspective view of a connecting structure of the stripperassembly of FIG. 11;

FIG. 13 is a partial perspective view of a gib of the connectingstructure of FIG. 12;

FIG. 14 is a cross-sectional view of the stripper assembly of FIG. 11along line A-A;

FIG. 15 is a cross-sectional view of the stripper assembly of FIG. 11along line B-B.

The drawings are not necessarily to scale and are sometimes illustratedby phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the embodiments or that render other details difficult to perceivemay have been omitted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIGS. 3, 4 and 5 illustrate the presently preferred states of operationof a mold 100 configured in accordance with the first embodiment (whichis the preferred embodiment).

FIG. 3 shows the mold in the closed position ready for injection of theplastic into the mold. The mold includes a mold base 160 that includes amolding stack 101. The mold base 160 includes a core plate 41, astripper plate 40, and a cavity plate 36. The stack 101 includes a moldcore 44 fitted into the core plate 41 and retained therein by a lockring 35 and bolts 45. The mold core 44 contains a cooling tube 46 forthe transmission of cooling fluid from a source within the mold core 44to remove heat from the injected material in the mold cavity 47 andsolidify the molded part in the mold cavity 47. The stack 101 includes acavity insert 32 and an adjacent gate insert 31 that are retained in thecavity plate 36 by a cavity flange 37 and bolts (not shown). Coolingchannels 48 circulate cooling fluid from a source through the cavityinsert 32 and gate insert 31 to remove heat from the injected material.The stack 101 includes a pair of molding inserts, such as the neck rings34 and 33 described hereinbefore, that are mounted to correspondingslide bars 38A and 38B, shown with reference to FIG. 6A, and supportedby a stripper plate 40 when the mold is in the closed and clampedposition shown in FIG. 3. Cooling channels 49 and 50 circulate coolingfluid from a source through the neck rings 33 and 34 to remove heat fromthe injected material.

FIG. 3 shows the stack 101 in the closed position. In this position,clamping force can be applied through the stack 101 by means of the gateinsert 31, cavity insert 32, neck rings 33 and 34 and lock ring 35 andby means of the cavity plate 36, cavity flange 37, neck rings 33 and 34and lock ring 35. In addition, because a confronting face 43 of theslide bars 38A and 38B are in firm positive contact with a confrontingface 51 of the stripper plate 40, clamping force can also be appliedthrough the neck rings 33 and 34 to the slide bars 38A and 38B and tothe stripper plate 40. As the slide bars 38A and 38B are in firmpositive contact with the stripper plate 40, the clamping force appliedthrough the slide bars 38A and 38B is applied to the stripper plate 40and into the core plate 41 to help retain the mold closed duringinjection.

In the prior art design, where a wear plate separated the slide barsfrom the stripper plate, any clamping force applied through the slidebars could not be reliably transferred through the stripper plate andinto the core plate because wear in the wear plate would, over time,result in an increasing component of the clamping force being directedthrough the stack.

FIG. 4 shows the stack 101 in a partially open position with no clampingforce being applied. The slide bars 38A and 38B are now separated fromthe stripper plate 40 by a slight gap 42. The manner in which this gap42 can be achieved will be illustrated and described with reference tothe three exemplary embodiments shown in FIGS. 6A, 6B 7A, 7B and 8. Ofcourse, those skilled in the art may on the basis of the foregoingembodiments derive other suitable alternatives.

FIG. 5 shows the stack 101 in the fully open position for releasing apreform, not shown, from the mold cavity 47. As shown in FIG. 5, theslide bars 38A and 38B have retracted the neck rings 33 and 34 whileremaining out of contact with the stripper plate 40.

In view of the foregoing, and shown with reference to FIGS. 3, 4 and 5,the wear plate 19 and clamping force block 29, shown in FIG. 1, are nowpreferably omitted.

The mold is operated in the same basic manner as similar molds in theprior art. The operation of these molds is well understood by thoseknowledgeable in the art of injection molding. Accordingly, adescription of the actual operation of the mold is not necessary to afull understanding of the exemplary embodiments and will therefore notbe provided herein. Implementation of the embodiments will be fullyunderstood from the illustration and description of the three separateembodiments shown in FIGS. 6A, 6B, 7A, 7B and 8 and fully describedhereinafter.

For purposes of illustration the gap between the stripper plate 40 andthe slide bars 38A and 38B has been exaggerated. The gap, during periodswithout an applied clamping force, may in fact approach zero and needonly be wide enough to ensure that the slide bars 38A and 38B do notcontact stripper plate 40 with any appreciable force during the slidingaction thereof to the extent that significant wear is avoided.

FIGS. 6A, 6B, 7A, 7B and 8 illustrate three exemplary embodimentsshowing how the slide bars 38A and 38B and stripper plate 40 can be heldin contact during injection and out of contact when opening the mold.

In a similar arrangement to the known mold of FIG. 1, the FIGS. 6A and6B show the first exemplary embodiment of the mold 100, as including aconnecting structure 161 slidably linking a pair of slide members 38Aand 38B to a stripper plate 40 of a mold base 160. The connectingstructure 161 includes a pair of connecting bars 66A and 66B slidablyarranged in a guide that is defined in the mold base 161 between agroove 67 formed in the stripper plate 40 and a pair of gibs 62A and 62Bthat are linked thereto. The gibs 62A and 62B are preferably made of anelastic material such as a nylon block. The selected material preferablyoffers high load bearing capabilities, good strength and wear resistanceand a low coefficient of friction. A nylon product such as is sold underthe registered trade mark ‘Nylatron’, a registered trade mark ofQuadrant DSM Engineering Plastic Products, may be suitable for use asgib material as it has the requisite strength and elasticity (i.e.Young's Modulus of about 2.76 GPa). Accordingly, when clamping force isapplied, the gibs 62A and 62B can be compressed sufficiently to enablethe slide bars 38A and 38B to come into contact with the stripper plate40 and enable the transfer of clamping force through the slide bars 38Aand 38B and into the stripper plate 40. When the clamping force isremoved, the gibs 62A and 62B decompress and lift the slide bars 38A and38B out of contact with the stripper plate 40 to form a gap 42 as shownin FIG. 6B and thus enable slide bars 38A and 38B to separate and openneck rings 33 and 34 and release a molded part.

Accordingly, and in view of the typical properties of Nylon, the gap ispreferably selected to be in the range between 0.5-3% of a thickness ofthe gib 62A and 62B and more ideally is in the range of between 2 and2.5%.

Notwithstanding the foregoing, the gap is preferably selected to be inthe range between 0.1 and 2.0 mm and more ideally is in the range ofbetween 0.4 mm and 0.5 mm.

In accordance with a second embodiment, a mold 200 is shown in which thegap may be controlled using a connecting structure 261, of a mold base260 that includes a cam arrangement as shown in FIGS. 7A and 7B. Tosimplify the drawings, only one cam roller is shown, FIG. 7A showsschematically, a partial section of a portion of the mold in the closedposition. FIG. 7B shows, schematically, a partial section of the moldportion in the open position. In FIGS. 7A and 7B, the connecting bar 71Ahas a cam surface 72 that cooperates with a cam roller 73 affixed tostripper plate 74. Connecting bar 71B has a similar cam arrangement thatcannot be seen in the drawing as illustrated in FIGS. 7A and 7B. Gib 75confines connecting bar 71B to the groove 76. A second gib wouldsimilarly confine connecting bar 71A to groove 76. Slide bar 77A isfirmly attached to connecting bar 71A and slides over stripper plate 74when connecting bar 71A reciprocates within groove 76. As cam surface 72travels over cam roller 73 to the position shown in FIG. 7B, a gap 42 iscreated between slide bar 77A and stripper plate 74. Initially the gap42 is small but sufficient to prevent wearing contact between the slidebar 77A and the stripper plate 74. When the connecting bar 71A hascompleted travel to fully open the slide bar 77A and associated neckrings such as neck ring 79, the gap between the stripper plate 74 andslide bar 77A can be substantial. A similar arrangement of cam roller,cam surface and slide bar is associated with connecting bar 71B topermit separation of neck rings on the opposite side of the cavity toneck ring 79.

With the use of the cam roller 73, the gap between the stripper plate 74and slide bar 77A is preferably selected to be in the range of 0.1 mm to10 mm but, is preferably kept within the range of 0.4 mm and 0.5 mm.

FIG. 8 is a schematic view of a mold 300 in accordance with a thirdexemplary embodiment. In FIG. 8, a connecting structure 361, of a moldbase 360, includes a compressible elastic pad 81 that is confined withina slot 82 in the surface of the stripper plate 83. Under clamping forcethe pad 81 is compressed to a level even with the surface of thestripper plate 83 thus enabling a firm and positive contact between theconfronting surfaces of the slide bar 84A and the stripper plate 83 whenclamping force is applied to the mold. As shown in FIG. 8, a singleelastic pad 81 is shown located between the connecting bar 85A and thestripper plate 83. The gib 86 confines the connecting bar 85A to thegroove 87 as has been described with reference to the prior art as shownin FIGS. 1 and 2. FIG. 8 shows the pad 81 in a decompressed state sothat a gap 42 separates the slide bar 84A from the stripper plate 83 anda gap 89 separates connecting bars 85A and 85B from stripper plate 83.When the slide bar 84A is in position to close the neck rings and themold is closed, clamping force can be applied and compress the pad 81 toclose the gap 42 and enable clamping force to be applied through theslide bars such as slide bar 84A and stripper plate 83.

In practice, any suitable number of pads could be provided and could belocated in the stripper plate, connecting bar or even the slide barsthemselves. The sole criteria is that the pads are compressed underclamping force and reliably return to a non-compressed state supportingand separating the connecting bars and slide bars from the stripperplate when clamping force is removed.

In accordance with another embodiment, not shown, the injection mold maybe configured to include a slide member for performing a furtheroperation that may include: removing a molded article from a moldingcavity of the mold; placing an insert in the molding cavity; orexercising a portion of the molded article.

The selection of a particular embodiment may be determined by thematerials available and the operating clamping forces required.

The above description has been given by way of example only and thatmodifications in detail may be made. For example, while the embodimentshave been described in terms of replacing the aluminum bronze gibs witha compressible elastic nylon rod, other materials having similarproperties of compressibility, strength and elasticity could be used.Similarly, those skilled in the art may easily arrive at substitutemeans for biasing the slide bars that are also within scope of theclaimed invention. For example, a prior art gib may be slidably arrangedon the stripper plate, in the direction of the applied clamping force,and further include a spring arranged therebeneath such that the slidemember is biased away from the stripper plate in much the same way asdescribed hereinbefore.

FIG. 9 is a cross-sectional view of a mold 400 in accordance with afourth exemplary embodiment. The fourth exemplary embodiment isconfigured to include a connecting structure (not shown) that is similarto the connecting structure 161 of the first exemplary embodiment asdescribed hereinbefore and shown with reference to FIGS. 6A and 6B. Inparticular, the connecting structure includes gibs (not shown) that areconfigured to provide a slight gap 42 between the confronting surfaces43 and 51 of the slide bars 438A and 438B and stripper plate 17 when themold is open. However in contrast to the first exemplary embodiment, themold is otherwise configured to avoid significant compression of thegibs (not shown) and instead directs the clamping force through thestack 1, and optionally through a clamping force block 29, whereby atleast some amount of the gap 42 is maintained while the mold isconfigured to be closed and clamped (as shown). Accordingly, the gibs(not shown) are preferably made from typical wear resistant materialssuch as Ampco, by Ampco Metal S. A. Corp of Switzerland. In so doing,the gibs (not shown) essentially replace the expensive wear plates ofthe prior art.

In accordance with a fifth exemplary embodiment, a mold 500 is shown inwhich the gap may be controlled using a connecting structure 561, of amold base 260 that includes a cam arrangement as shown in FIG. 10. Thecam arrangement is similar to the second embodiment shown in FIGS. 7Aand 7B except that the cam surface 573 is provided along an inclinedportion of a top surface of the gib 575 and the cam follower, not shown,is preferably provided along a similarly inclined surface formed throughthe confronting surface on the bottom of the slide 577A. As the camfollower surface, not shown, travels over the cam surface 573, as theslide moves between an in-mold and out-mold positions, a gap 42 iscreated between slide bar 577A and stripper plate 74.

With reference to FIG. 11, a stripper plate assembly of a mold 600 inaccordance with a sixth exemplary embodiment is shown. The stripperplate assembly includes a mold base 660 and a connecting structure 661.The connecting structure 661 is similar to the connecting structuresdescribed hereinbefore for providing a slight gap 42 between confrontingsurfaces 43 and 51 (FIG. 15) of a stripper plate 674 and slide members638A and 638B, respectively, responsive to the opening of the mold 600,the gap 42 closing responsive to a closing of the mold 600, or with thefurther application of a mold clamping force. Advantageously, but not anecessity, a clamping force may be transferred across the confrontingfaces 43 and 51 when the mold 600 is closed. The connecting structure661 is otherwise operable for movement of the neck rings (not shown)between an in-mold and an out-mold position, as described hereinbefore.

In the exemplary embodiment, the connecting structure 661 links fourcomplementary pairs of slide members 638A, 638B to the mold base 660.Each slide members 638A, 638B, generally consists of a rectangular barmember. A bottom face of the bar provides the confronting face 51. Eachslide member 638A, 638B, includes a plurality of mounting interfaces 640configured along a top face of the bar for receiving the neck rings (notshown). Each slide member 638A, 638B, also includes a plurality ofopenings 639 passing between the top face and the bottom face of the barfor accommodating both the neck rings (not shown) and the cores (notshown). Each slide member 638A, 638B, also includes a set of passages637, 639 (FIG. 15) extending between the sides of the bar, in proximityto each end of the bar, for receiving corresponding pairs of connectingmembers 666A, 666B. The connecting members 666A, 666B link correspondingslide members 638A, 638B of the four pairs of slide members 638A, 638Btogether as will be explained in detail hereinafter. Each slide member638A, 638B, also includes a coolant channel 638 (FIG. 15) extendingthrough the bar for providing a coolant to the neck ring mountinginterface 640. Fittings 648 provided at interfaces to the coolantchannel 638, at the ends of the bar, connect the coolant channel 638 tocorresponding coolant channels (not shown) provided in the stripperplate 674 via hoses 682. Each slide member 638A, 638B also includes apocket 645 (FIG. 12) formed through the bottom face at the base of thebar, in proximity to each end thereof, for accommodating a gib 650, asexplained hereinafter. The outermost slide members 638A, 638B, of thefour pairs of slide members 638A, 638B, are configured to include anactuator interface 641 (alternate actuator interface 641′ shown withreference to FIG. 12) for cooperation with a slide member actuator. Inthe present embodiment the slide member actuator includes a bracket 646,a cam follower 644, and a cam (not shown). Alternatively, the slidemember actuator could include any one of a variety of actuators such aspneumatic, hydraulic, electromechanical, and the like.

With reference to FIG. 15, within each set of the passages 637, 639, ofthe slide members 638A, 638B, the first passage 637 is preferablyconfigured to fit relatively closely around the outer surface of theconnecting members 666A, 638B relative to the second passage 639 whichis configured to provide a small clearance. In this way, the firstpassage 637, preferably in cooperation with a retainer 668, such as aset screw, prevents relative motion between the slide member 638A, 638Band the corresponding connecting member 666A, 666B thereby linkingrespective slide members 638A, 638B of the four pairs of slide members638A, 638B together. Likewise, the second passage 639 allows forrelative motion between the slide members 638A, 638B andnon-corresponding connecting member 666A, 666B.

The mold base 660 includes the stripper plate 674. The mold base 660also includes leader pin bushings 678, a mold foot 680, and ejectorlinkages 676, 677 (FIGS. 14 & 15). The leader pin bushings are forcooperating with leader pins (not shown) for aligning the stripper plateassembly of the mold base 160 with other members (not shown) of the moldbase 160. The mold foot 680 cooperates with other mold feet (not shown)for supporting the mold base 660 when the mold 600 is outside of theinjection molding machine (not shown). The ejector linkages 676, 677 arefor linking the stripper plate 674 with an ejector mechanism in themolding machine for movement of the stripper plate assembly relative tothe other members (not shown) of the mold base 160.

With reference to FIG. 12, a bottom view of the connecting structure 661linking the slide members 638A, 638B reveals the arrangement of the gibs650 within the pockets 645 as provided in the base of the slide members638A, 638B. With further reference to FIG. 13, each gib 650 includes ablock 652 through which a tubular bushing 656 is slidably arranged. Aflange 658 provided at an end of the bushing 656 provides an upper stopto limit the travel of the block 652. With reference to FIG. 14, thetravel of the block is otherwise limited by a lower stop provided by atop surface of the stripper plate 674. Again with reference to FIG. 14,the portion of the bushing 656 that is shown extending through the block652 is received within a complementary bore 675 provided through a topportion of the stripper plate 674. The depth of the bore 675 relative tothe maximum extent to which the bushing 656 may extend through the block652 (when the block is at its upper limit against the flange 658) isestablished such that the block 652 has a limited degree of freedom toslide (stroke) vertically on the bushing between the limits. The strokeis preferably about 0.1 mm but the amount may be more or less. The block652 otherwise includes a pair of guides 690, such as linear bearings,retained therein by retainers 692. The guides 690 are configured tocooperate with an outer surface of the connecting members 666A, 666B toaccommodate a sliding of the connecting members 666A, 666B towards andaway from one another to provide for the opening and closing of the neckrings (not shown). Accordingly, the connecting members 666A, 666B arepreferably cylindrical rods, such as linear rails.

With reference to FIG. 14, the connecting structure 661 further includescompressible members 696, such as die springs, air springs, pneumaticactuator, and the like, set into bores provided beneath each end of theblock 652. The compressible members 696 act to urge the block 652against the upper stop, and in this way urge the interconnected slidemembers 638A, 638B upwardly to form the gap 42 between the confrontingsurfaces 43 and 51 when the mold 600 is open. Alternatively, thecompressible member may include a pair of o-rings (not shown) arrangedin seats 697 configured between the stripper plate 674 and the block652.

The description of the exemplary embodiments provides examples of thepresent invention, and these examples do not limit the scope of thepresent invention. It is understood that the scope of the presentinvention is limited by the claims. The concepts described above may beadapted for specific conditions and/or functions, and may be furtherextended to a variety of other applications that are within the scope ofthe present invention. Having thus described the exemplary embodiments,it will be apparent that modifications and enhancements are possiblewithout departing from the concepts as described. Therefore, what is tobe protected by way of letters patent are limited only by the scope ofthe following claims.

1. An injection mold, comprising: a mold base having a confrontingsurface; a slide member having a complementary confronting surface; aconnecting structure slidably linking the slide member to the mold basefor a movement of said slide member between an out-mold position and anin-mold position; the connecting structure further configured tomaintain a gap between the confronting surface and the complementaryconfronting surface during at least a portion of the movement of theslide member between the out-mold position and the in-mold position sothat wearing of the confronting surface and the complementaryconfronting surface are reduced; the connecting structure is furtherconfigured to enable a positive contact between the confronting surfaceand the complementary confronting surface in response to an appliedclamping force between the slide member and the mold base; wherein theconnecting structure includes: a connecting member connected to theslide member; a gib having a block through which a tubular bushing isslidably arranged; the tubular bushing having a flange that provides anupper stop to limit a travel of the block; a portion of the tubularbushing received within a complementary bore defined through a topportion of a plate, of the mold base, to a depth that permits the blocka limited degree of freedom to slide on the tubular bushing between theupper stop and a lower stop provided by a top surface of the plate; aguide arranged in the block, the guide configured to cooperate with theconnecting member to accommodate a sliding of the connecting member; acompressible member arranged between the mold base and the block to urgethe block against the upper stop and in this way urge the slide memberupwardly to form the gap.
 2. The injection mold of claim 1, wherein theconnecting structure is configured to maintain at least a portion of thegap when the slide member is arranged in the in-mold position.
 3. Theinjection mold of claim 1, wherein the slide member is configured forreceiving a molding insert for defining a molding cavity in theinjection mold.
 4. The injection mold of claim 1, wherein the slidemember is configured for performing a further operation, wherein thefurther operation includes at least one of: removing a molded articlefrom a molding cavity of the injection mold; placing an insert in themolding cavity; exercising a portion of the molded article.
 5. Theinjection mold of claim 1, wherein the gap between the confrontingsurface and the complementary confronting surface is between 0.1 mm and2.0 mm.
 6. The injection mold of claim 1, wherein the connectingstructure includes: a guide linked to said mold base configured forslidably receiving the connecting member.
 7. The injection mold of claim6, wherein the guide is defined between a surface of a groove formed inthe mold base and a surface of the gib that is linked to the mold base.8. An apparatus for slidably linking a slide member to a mold base in aninjection mold, the mold base having a confronting surface, the slidemember having a complementary confronting surface, the apparatuscomprising: a connecting structure configured to maintain a gap betweenthe confronting surface and the complementary confronting surface duringat least a portion of a movement of the slide member between an out-moldposition and an in-mold position so that wearing of the confrontingsurface and the complementary confronting surface is reduced; theconnecting structure is further configured to enable a positive contactbetween the confronting surface and the complementary confrontingsurface in response to an applied clamping force between the slidemember and the mold base wherein the connecting structure includes: aconnecting member connected to the slide member; a gib having a blockthrough which a tubular bushing is slidably arranged; the tubularbushing having a flange that provides an upper stop to limit a travel ofthe block; a portion of the tubular bushing receivable within acomplementary bore defined through a top portion of a plate, of the moldbase, to a depth that permits the block a limited degree of freedom toslide on the tubular bushing between the upper stop and a lower stopprovided by a top surface of the plate; a guide arranged in the block,the guide configured to cooperate with the connecting member toaccommodate a sliding of the connecting member; a compressible member696 arranged between the mold base and the block to urge the blockagainst the upper stop and in this way urge the slide member upwardly toform the gap.
 9. The apparatus of claim 8, wherein the connectingstructure is configured to maintain at least a portion of the gap whenthe slide member is arranged in the in-mold position.
 10. The apparatusof claim 8, wherein the slide member is configured for receiving amolding insert for defining a molding cavity in the injection mold. 11.The apparatus of claim 8, wherein the slide member is configured forperforming a further operation, wherein the further operation includesat least one of: removing a molded article from a molding cavity of theinjection mold; placing an insert in the molding cavity; exercising aportion of the molded article.
 12. The apparatus of claim 8, wherein thegap between the confronting surface and the complementary confrontingsurface is between 0.1 mm and 2.0 mm.
 13. The apparatus of claim 8,wherein the connecting structure includes: a guide linked to said moldbase configured for slidably receiving the connecting member.
 14. Theapparatus of claim 13, wherein the guide is defined between a surface ofa groove formed in the mold base and a surface of the gib that is linkedto the mold base.